While I already have this posted over at Rootzwiki, I figured it would make sense to post it over here for the wider audience. There may be some parts missing from here (copying useful parts over, and the thread covers a few months), but the full thread can easily be found. I am using Timur's ROM, and installing the Nexus into my 2006 Audi A4. Ever since I bought the car I have been annoyed/disappointed with the factory stereo, for one thing it has a tape deck (why a car made in 2006 has a tape deck, is something that will forever confuse me). It also has no bluetooth, no GPS, no way to add an aux input except using a cassette type adaptor. All in all, its pretty limited. My options for replacing it were either an RNS-E ($800+) or an aftermarket unit (cost of aftermarket unit + approximately $200 in wiring to get it functional).
I have already replaced everything downstream of the head unit, starting with a JBL MS8, I then have a pair of Alpine amplifiers running all of my speakers. The sound is good, but just something about the original head unit always bugged me. On an Audi forum I am a member of, I recently saw someone had mentioned they were looking to install an iPad into their dash. That got the wheels turning, and before you know it. I was holding my wifes Kindle Fire up to the dash.
Since the fitment was good, I decided to go ahead with the project. Bought a 16GB Nexus 7, I went with the 16GB because I don't plan to store a whole lot on the tablet itself. I also started ordering a bunch of supplies that I would need:
12V DC-DC Regulator
90 degree mini USB connector
I thought about leaving the Nexus stock for a couple weeks, but after about a day rooted it and flashed with Timur's USB ROM. I removed my stock head unit from the car, plugged the JBL MS8 into the 3.5mm output, and nothing. I then realized that the MS8 currently gets a remote turn on signal from my OEM head unit. Currently I am trying to locate a switchable 12V somewhere, but likely will end up using the fuse tap.
Here is where things look so far:
The kit is not pushed all the way back in, this was really just for test fitment purposes. Since I don't yet have the fuse tap, I want to keep my OEM head unit in there for a couple more weeks. Mental note: If you think you are going to sneeze when using a Dremel, switch off the Dremel:
In order to get the Nexus to sit flush, I had to dremel off some material on the back of the dash kit. The scratch is only noticeable at certain angles, but I may well pick up another dash kit at some point. Once my 90 degree USB connector arrives I need to figure out which of the area's in red below I need to cut some away from. They are simply plastic, that I think help hold the stock head unit in place. So I should be able to cut a notch out for the USB cable to go through:
That's about the extent of my progress for now. As I am currently waiting on a few things to arrive in the mail. Ultimately I will have the Nexus semi permanent in the dash (I want to be able to remove it if parked in high crime areas), USB-OTG cable plugged in, then a USB hub, with the USB-DAC sending signal to the MS8, and an iPod flashed with Rockbox as external storage in the glovebox for music. I plan to use my cell phone and bluetooth tethering for streaming music / navigation. At some point I am also going to pick up a Connects2 harness and Joycon to retain my steering wheel controls, and am also keeping an eye on the useage of an easycap in order to add a back up cam.
Edit: Had a few people asking me for the launcher, it should now be attached to this post. The black border was in order to keep the image centralized on my home screen. Along with this image I just used UCCW to create hotspots for opening the apps.
Pulled out the glovebox, knee bolster on the drivers side and trunk trim in order to run wiring. I had to run a new remote turn on wire to my MS8 as there is no switchable 12v in the trunk. Power and ground to the fuse box area, and I wanted to run a USB extension into the glovebox for my flash drive.
For now I ended up removing the inline fuse that I was using behind the fuse box on the 12v going to the 12v regulator, I may add it again, but have it tapped into a fused circuit, so not sure I need to.
I got 99% of things working today, my ground wire to the USB hub needs to be re-done. The wires are so thin that the splice was not working, for now I just have them twisted together. I did get music playing through the MS8, and my USB flash drive was mounting fine. The other issue I am running into is when I turn off the ignition, the hub loses power instantly, causing the Nexus to give me a warning about improper removal of USB storage. I am trying to find out if there is a way to use Tasker to unmount the storage. But, I don't think I can get it to work, as the second the ignition goes off, the hub loses power. I may just have to manually unmount each time (which sucks).
The other thing is that I need to trim some more plastic to the right of the tablet, due to the 90 degree micro USB adapter, and charger cable, the dash trim does not seem to fit in properly. I am planning to finish these pieces up tomorrow, and then see how it does with my commute to work on Tuesday.
I glued a couple small pieces of foam at the top to push the Nexus outwards, I may add something to the bottom as well to make it sit a little more flush. Somewhat afraid to remove it at the moment though, due to the USB issue with the cable being knocked slightly causing it to lose connection. I do want to think of a solution though, as like I said, I want to be able to remove it from the car.
Took a quick test drive into town and back (about 30 miles of driving) audio / power did not cut out at all. Battery went from 78% when I left, and was back up to 83% when I got home. Spent half the time streaming music from the flash drive, the other half streaming over Slacker using Bluetooth tethered to my cell phone.
Next steps are to save up for a CAN-BUS interface, and then pick up a Joycon. Having had to change the volume via the screen, I want to use steering wheel controls. It's difficult to accurately adjust the volume, so I want the steering wheel option back. I also need to try and think of what to do with the USB. If I can find a charger cable with a shorter plug section, that may work as I can remove the 90 degree bend. But, most I have looked (I have 3 different kinds laying around the house) all have a similar length to them. I also need to re-calibrate my MS8, the center image is slightly off to the left with the Nexus. I am also likely going to refine my Tasker profiles at some point.
The one issue I did have after going for a drive, was that the Nexus froze when I got home. I am 99.9% sure it was my fault though. When I was running wires, I had the battery disconnected, which caused my key-fob remote to be out of sync with the car. To sync it back up, you put it in the ignition, turn the ignition on, push the lock button, then turn the ignition off again. I did this in fairly quick sequence, which I think caused Tasker to lock up as it was still powering everything on, when I removed power again. I had to pop the dash trim off, and reboot using the power button. Working fine now though (still need to sync the key).
I drilled a larger hole today for my new USB cable (the hole is a mess as I had to use my Dremel, and there is 0 room to work there, especially as the tan piece to the right is a visible piece of the dash that I don't want to tear up):
What's annoying is that while USPS say my new cable has been delivered, it's not in my mailbox
Next thing I need to do is figure out a better way to make the Nexus sit flush against the bezel. I could tape it, but would prefer not to do that. In the first picture above, the blue box is around a piece that I glued some foam to, but it came off (I only used a small amount of glue). I may go this route again, the only other option is to try to fabricate some kind of hook system to the back of the bezel, but I am there is not much room on the back:
The advantage to making some kind of hook system though, is that it will likely hold the tablet nicely against the bezel, and make it a little easier for removal/installaiton. You can see in the bottom right of the bezel where I had to cut a section out, this kept pushing on the power / volume rocker when I was installing it in the car causing it to either end up muted, or power off.
I wish that cable were in my mailbox!! I might try to get things working in its current configuration at least for my drive to work tomorrow. Chances are I will get annoyed with it cutting out though, and give in.
Edit: So, just went down to the garage to take a look at things. Seems like I need a new OTG cable, I was looking at the male end of mine that would plug into the Nexus, and noticed it at a slight angle, if I touch it, I see it spark. Not sure if that's a result of it being a cheap Chinese cable, or the plug being pushed at an angle by the dash. Either way it means I am now having to find another OTG Y-cable, which I will be lucky to get before Monday. I may try to look inside at the pins, just to make sure there is not something that has fallen in there causing a short. But, at the same time am not sure I want to risk my equipment on it.
Thankfully I can use my phone to listen to music on the way to work and back.
Here is my awesome fix for getting rid of the gap:
Yes, that is elastic from some underwear. LOL. I did not want to buy some elastic if it did not work, so figured what the heck, use some elastic from some boxer shorts. Works perfectly, holds the Nexus up against the bezel, and is strong enough that I can hold onto the plastic with the Nexus in there, and it won't fall out.
The gap that is left though is due to a slight curvature in the bezel:
Currently I am not sure what to do about that piece, if I try to sand it flat then I essentially am going to have to sand the top and bottom lip away almost completely. I have a new trim piece coming that should match the interior a little better, not sure if that is curved or not yet though, if it is as well, I may just deal with that piece. When it's in the car it's not too bad, and I don't know that I want to eliminate the bottom/top lip to have that piece flat.
Also, since I don't think I posted this picture yet, here is the downward facing micro USB cable from usbfirewire.com:
After getting the Joycon installed, I also went ahead and ended up ordering a DCDC-USB, I had been having various odd issues and it turns out that most of them were a combination of poor power, and poor connections. I created a pigtail to connect to the DCDC-USB that has 2 female USB ports, one of them provides power to the hub, the other to the Nexus. Also running a Jabra Journey to route phone calls through. Charging rate is awesome, my battery typically gets to full during a single drive to work, and remains full all week long. Here is how the Nexus currently sits in the dash:
And here is a launcher I am working on:
It's supposed to mimic the RNS-E, so far it's not quite where I want it to be as I want to use %MTRACK to have a basic text of what song is playing, and not use the current widget. Apart from that though I am pretty happy with it.
Next things to do are to try and program a button on my steering wheel to activate voice search on the Nexus, possibly a back up camera and that's about it really.
Almost every OEM adds its own unique flair to their stock firmwares. While some of … more
18 Sep 2014
By Tomek Kondrat
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